Lawler told The Oklahoman that the changes are part of an ongoing effort to reduce expenses and improve performance.

"On behalf of the entire company, I want to express our gratitude to Steve, Jeff, Steve and Martha for their many years of service and dedication," Lawler wrote. "Each of these executive leaders has contributed greatly to Chesapeake, and we wish them the very best in their future endeavors.

"I have great confidence in the operations, drilling, and HR teams," he said in the email. "I will continue to be directly engaged in each of these important areas, and I have appointed interim management responsibility as we move forward with our operational strategy shift."

Chesapeake co-founder and former CEO Aubrey McClendon left the company in April while senior vice presidents Tom Price and Henry Hood left the company in May.